It has long been desirable to have a removable auxiliary lens assembly attached to eyeglasses. Typically, the auxiliary lenses provide some function not provided by the primary lenses. For example, the auxiliary lenses may be glare-reduction lenses (sunglasses), while the primary lenses are corrective. Various combinations are possible.
Conventionally, the auxiliary lens and frame assembly is removably secured to the primary assembly by any of a number of mechanical arrangements. The auxiliary assembly typically is forward or in front of the primary assembly, meaning the primary assembly is nearer or closer to the wearer's eyes. One drawback to this arrangement is that the auxiliary assembly can detract from the aesthetic appearance of the primary assembly, which is often purchased based on its aesthetic appearance. The purchase motivated by aesthetic appearance is particularly applicable to sunglasses with glare-reduction lenses.
U.S. Pat. No. 6,062,688, May 16, 2000, to Vinas discloses a safety shield assembly that is mounted between the primary frame of an eyewear assembly and the wearer's eyes. The purpose of the safety shield is to enclose the area between the wearer's face and the frame. The safety shield is formed of foam rubber to provide an air-permeable shield. This disclosure fails to provide an auxiliary lens assembly and, by its nature as a safety shield, is functional rather than aesthetic and actually detracts from the aesthetic appearance of the eyewear assembly.
A need exists, therefore, for improved means for attachment of auxiliary lens assemblies to primary lens assemblies that is both robust in its attachment, yet easily manufactured and permits breadth in design characteristics.